Method for making spherical particles

Patent 4643753 Issued on February 17, 1987. Estimated Expiration Date:

August 7, 2005. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

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Inventor

Braun, Rudolf K.

Assignee

Potters Industries, Inc. (NJ)

Application

No. 06/763293 filed on 08/07/1985

US Classes:

65/21.3, Spheroidizing or rounding of solid glass particles425/90, WITH MEANS APPLYING COATING (E.G., PARTING, ETC.) MATERIAL TO WORK OR WORK CONTACT MEANS431/3, Decarbonizing, cleaning or purging431/8, Flame shaping, or distributing components in combustion zone65/22, With pore forming in situ65/23With destruction or delamination of transitory attached or associated separate material

Examiners

Primary: Lindsay, Robert L.

Attorney, Agent or Firm

Robinson, Jr.; Lee C.

International Classes

C03C 17/22 (20060101)
C04B 18/00 (20060101)
C04B 18/02 (20060101)
B01J 2/16 (20060101)
B01J 8/26 (20060101)
B01J 8/24 (20060101)
C03B 19/00 (20060101)
C03B 19/10 (20060101)

Abstract

A process and apparatus for spheridizing irregularly shaped minute particles, and the spheres produced thereby, in which a thin carbonaceous coating is applied to the particles in a unique manner, and in a preferred embodiment the particles are then advanced through successive fluidizing beds. The first bed has an inert atmosphere and is maintained at an elevated temperature sufficiently high to allow surface tension to shape the particles into spherical form while in a fluidized condition in the first bed. The spherical particles are then advanced through successive additional beds where they are cooled to an intermediate temperature sufficient to solidify the particles, are subjected to an oxidizing atmosphere which completely removes the coating, and are then further cooled while being maintained in a fluidized condition. The inert gaseous atmosphere within the first bed is continuously withdrawn and recycled through the system.